Infection of Protoplasts from Several Brassica Species with Cauliflower Mosaic Virus Following Inoculation Using Polyethylene Glycol

Using a polyethylene glycol-mediated uptake procedure, protoplasts from a range of Cruciferous species were infected with cauliflower mosaic virus; they include Moricandia arvensis, a plant not k n o w n to be susceptible. With this technique > 90~o of turnip protoplasts were infected, each producing an average of 104 to 105 viral genome equivalents. Filter hybridization and fluorescent antibody staining showed that virus synthesis in turnip protoplasts reaches a maximum 65 to 96 h postinoculation. In protoplasts from some other species the time course was different; viral D N A synthesis in rape reached a maximum 24 to 48 h post-inoculation, approximately 48 h before the maximum accumulation of viral antigen.